Trehalose and mannitol metabolism in the edible mushroom Agaricus bisporus

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A comparison of gastroenteritis in a general practice-based study and a community-based study.

We compared gastroenteritis cases that consulted a general practitioner (GP) with those who did not in a community-based study and also with those in a GP-based study. We aimed to identify factors associated with consultation, and with inclusion of cases by GPs, and secondly to study the effects on the frequency of detection of pathogens. Furthermore, we estimated the under-ascertainment by GPs. Both studies were performed in The Netherlands in the same population in an overlapping time-period. Overall, 5% of community cases consulted a GP. Cases who consulted suffered from more severe episodes than non-consulting cases. Inclusion of cases by GPs, instead of a study team, caused a selection of more severe cases with more chronic symptoms. When extrapolating data from GP-based studies, it should be taken into account that, in general practice, gastroenteritis due to bacteria and Giardia lamblia is a relatively large proportion of that in the community and gastroenteritis due to Norwalk-like viruses is a relatively small proportion. The incidence of gastroenteritis in general practices was estimated between 14 and 35 per 1000 person years

Surveillance of zoonotic bacteria in farm animals in The Netherlands. Results from January 1998 until December 2000

To obtain reliable quantitative data on the occurrence of zoonotic bacteria in farm animals in The Netherlands, a surveillance programme was implemented in April 1997. Results for January 1998 through December 2000 are presented in this report. In this period, faecal samples from in total 2,378 flocks/herds of layers, broilers, finishing pigs, dairy cattle and veal calves were examined for the presence of Salmonella spp., Campylobacter spp. and/or verocytotoxin-producing E. coli O157. Questionnaires were used to obtain data for risk factor analyses. For layers, prevalences of salmonella positive flocks were 12% (1998, using Rappaport-Vassiliadis (RV) as selective enrichment medium) and averaged around 20% in 1999 and 2000 (using both RV and modified semisolid RV (MSRV)); for broilers, the salmonella prevalence declined from 28% (1998, RV) to 16% (2000, RV & MSRV). For finishing pig, 34% (1998; 4th quarter only), 13% (1999) and 16% (2000) positive herds were identified, while for dairy cattle and veal calves, salmonella prevalences were around 3% (based on the use of RV only). Serotype discrimination showed the predominance of S. Enteritidis (mainly phagetype PT4) in layers in all years; for broilers this serotype prevailed until 1999, whereas S. Paratyphi B var. Java prevailed in 2000. In finishing pigs, S. Typhimurium predominated, with an increase of phagetype DT104 during the study period. The campylobacter prevalence in broilers decreased from 31% (1998) to 18% (1999), reaching 24% in 2000. Finishing pigs, dairy cattle and veal calves showed lower campylobacter prevalences for 1999 compared to 1998. C. jejuni was the dominating species in broilers and dairy cattle, whereas C. coli predominated in pigs; both species prevailed equally in veal calves. Prevalence estimates for E. coli O157 in dairy cattle were 5% (1998), 8% (1999) and 6% (2000; 8% with an adjusted processing of samples); for veal calves these were 5% (1998), 9% (1999) and 11% (2000; 17% with the adjusted method). PCR-test results revealed the presence of the virulence associated SLT- and/or eae-genes in all isolates examined. Potential risk factors were identified for E. coli O157 in dairy cattle and for Campylobacter spp. in broiler

Sensor, a population-based cohort study on gastroenteritis in the Netherlands: incidence and etiology.

A prospective population-based cohort study with a nested case- control study was conducted to estimate the incidence of gastroenteritis and the associated pathogens in the general Dutch population. Follow-up of two consecutive cohorts was performed by weekly reporting cards from december 1998 to december 1999. Cases and controls in the case-control study supplied a questionnaire and stool samples. The standardized gastroenteritis incidence was 283 per 1,000 person-years. The incidence rose with increasing level of education and was higher for persons with a history of diarrhea and for young children. Bacterial pathogens accounted for 5% of cases, bacterial toxins for 9%, parasites for 6%, and viral pathogens for 21%, with Norwalk-like virus (NLV) as the leading pathogene in 11% of cases. The gastroenteritis incidence was higher than that reported for England, but lower than for the United States. In community cases, viral pathogens are the leading cause of gastroenteritis, with NLV being the number one cause of illness in all age groups but one. In many countries, preventive measures are implenmented to decrease bacterial infections. However, additional prevention of viral infections, especially NLV, might significantly decrease the number of gastroenteritis cases in the community. (aut. ref.

Surveillance of zoonotic bacteria in farm animals in The Netherlands. Results from January 1998 until December 2000

To obtain reliable quantitative data on the occurrence of zoonotic bacteria in farm animals in The Netherlands, a surveillance programme was implemented in April 1997. Results for January 1998 through December 2000 are presented in this report. In this period, faecal samples from in total 2,378 flocks/herds of layers, broilers, finishing pigs, dairy cattle and veal calves were examined for the presence of Salmonella spp., Campylobacter spp. and/or verocytotoxin-producing E. coli O157. Questionnaires were used to obtain data for risk factor analyses. For layers, prevalences of salmonella positive flocks were 12% (1998, using Rappaport-Vassiliadis (RV) as selective enrichment medium) and averaged around 20% in 1999 and 2000 (using both RV and modified semisolid RV (MSRV)); for broilers, the salmonella prevalence declined from 28% (1998, RV) to 16% (2000, RV & MSRV). For finishing pig, 34% (1998; 4th quarter only), 13% (1999) and 16% (2000) positive herds were identified, while for dairy cattle and veal calves, salmonella prevalences were around 3% (based on the use of RV only). Serotype discrimination showed the predominance of S. Enteritidis (mainly phagetype PT4) in layers in all years; for broilers this serotype prevailed until 1999, whereas S. Paratyphi B var. Java prevailed in 2000. In finishing pigs, S. Typhimurium predominated, with an increase of phagetype DT104 during the study period. The campylobacter prevalence in broilers decreased from 31% (1998) to 18% (1999), reaching 24% in 2000. Finishing pigs, dairy cattle and veal calves showed lower campylobacter prevalences for 1999 compared to 1998. C. jejuni was the dominating species in broilers and dairy cattle, whereas C. coli predominated in pigs; both species prevailed equally in veal calves. Prevalence estimates for E. coli O157 in dairy cattle were 5% (1998), 8% (1999) and 6% (2000; 8% with an adjusted processing of samples); for veal calves these were 5% (1998), 9% (1999) and 11% (2000; 17% with the adjusted method). PCR-test results revealed the presence of the virulence associated SLT- and/or eae-genes in all isolates examined. Potential risk factors were identified for E. coli O157 in dairy cattle and for Campylobacter spp. in broiler

Enhanced laboratory-based surveillance of Shiga-toxin-producing Escherichia coli O157 in The Netherlands.

The aim of this study was to analyse the results of a programme in the Netherlands for enhanced surveillance of Shiga-toxin-producing Escherichia coli (STEC) O157. In this programme, implemented in January 1999, all laboratories report positive cases to the public health services and submit isolates for typing to the reference laboratory. Public health services collect clinical and risk factor information of patients, using a standardised questionnaire. Results were analysed for the first two and a half years of the programme. In February 2000, a questionnaire was sent to all laboratories to assess (i) the criteria for testing faecal samples for STEC O157, (ii) the diagnostic tools used, and (iii) the level of participation in the surveillance programme. Between January 1999 and June 2001, 93 cases of symptomatic STEC O157 infection were reported, 25% of which occurred in children aged 0-4 years. Serotyping for O, H and stx types showed that two types dominated, O157:H7, s tx2 positive (48%) and O157:H-, stx1 and stx2 positive (24%). Analysis of the 93 isolates by pulsed-field gel electrophoresis showed 17 clusters of isolates with at least 95% fragments in common, including isolates with unknown epidemiological links. Of the patients for whom questionnaire information was reported, 38% were hospitalised, 15% developed haemolytic uraemic syndrome, and 52% reported a known risk factor, such as contact with farm animals or manure, consumption of raw or undercooked beef, consumption of raw milk or cheese made from raw milk, or contact with a symptomatic individual. Response to the laboratory survey was high (97%). Only 6% of the laboratories carried out testing for non-O157 STEC, although 95% performed testing for STEC O157. The majority (88%) used culture on sorbitol MacConkey agar or sorbitol MacConkey agar with cefixime and tellurite as the method of detection of STEC O157. The identity of the strains was confirmed primarily with commercially available latex agglutination assays (95% of laboratories) and biochemical characterisation with the API 20E test (bioMerieux, France) (42% of laboratories). Most laboratories (92%) used selection criteria for testing, especially bloody diarrhoea and other clinical information (81% of laboratories) and young age (10%). It is concluded that STEC O157 is a limited public health problem in the Netherlands, although the selective testing policy and the low sensitivity of the culture techniques used probably caused the incidence of STEC O157 infection to be underestimated